EP2594721A2

EP2594721A2 - Insulated glass unit

Info

Publication number: EP2594721A2
Application number: EP12193241.2A
Authority: EP
Inventors: Jens Bøndergaard
Original assignee: VKR Holding AS
Current assignee: VKR Holding AS
Priority date: 2011-11-18
Filing date: 2012-11-19
Publication date: 2013-05-22
Anticipated expiration: 2032-11-19
Also published as: EP2594721A3; EP2594721B1

Abstract

A spacer for an insulated glass unit with two panes 1,2 spaced apart by the spacer 4 and comprising an intermediate film 3. The intermediate film 3 is fixed to the spacer 4 by means of a spring element 5. The spacer 4 has a cavity adapted for fixing the film 3 and spring 5. The cavity has a slanted shape 4b to provide a stretching effect.

Description

The exemplary and non-limiting embodiments of this invention relate generally to an insulated glass unit and more particularly to fixing an intermediate film arrangement in the insulated glass unit (IGU) by means of a spacer.

BACKGROUND ART

Windows, doors or buildings may have insulated glass units (IGU) where two or more panes or substrates are separated by a spacer. Some IGU employ an intermediate film between the panes. With respect to film solutions there are some previously described ways of fixing a film.
US4520611 discloses a film stretching member that imparts a force in a direction angularly displaced to the film surface.
US4334398 shows (fig. 10) holding of films 1 by circular tubes 8 inserted into a spacer cavity.

DISCLOSURE OF THE INVENTION

Insulating glazing units (IGUs) with three or more glass layers are too heavy for standard usage in sizes above a certain threshold. One way of lowering the weight of IGUs significantly is to substitute glass with lower density materials such as polymer sheets or films.
It would be desirable to provide an insulated glass unit with an intermediate film where the glass unit has a low weight and large view area (the spacer has low height i.e. also known as low profile).
Further it would be desirable to provide a glass unit with an intermediate film providing reduced heat loss while maintaining a high reliability i.e. long lifetime. And further it would be desirable to accommodate the intermediate film such that assembly is efficient while accommodating the pull from the stretched film.
The invention relates to an insulated glass unit according to claim 1 and use of the system according to claim 15.
Favourable embodiments are defined in the dependent claims.
Other objectives, features and advantages of the present invention will appear from the following detailed disclosure, from the attached dependent claims as well as from the drawings.
Generally, all references to "a/an/the [element, means, etc]" are to be interpreted openly as referring to at least one instance of the element, means, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present description, the invention will be explained in more detail with reference to the preferred embodiments shown in the drawings, in which

Fig. 1 shows a of an insulated glass unit with an intermediate film.
Fig. 2 shows a of an insulated glass unit with two intermediate films.
Fig. 3-4 show examples of two-part spacers with an intermediate film.

DETAILED DESCRIPTION

It is an objective to provide a low weight insulated glass unit which accommodates an intermediate film 3 to enhance the insulation while maintaining low weight. Another objective is to accommodate the film 3 and maintain the film stretched in an insulated glass unit that has thermal expansion and contraction. Another objective is an efficient assembly and fixing of the film.
Another objective is to provide a spacer with a low profile which enables a large view area for the IGU.
The present invention provides a spacer system for insulating glazing units in which the spacer 4 fixates one or more films 3 that are suspended inside the enclosed volume spanned by the spacer. The plane of the film 3 is substantially parallel with the panes 1,2. Figure 1 shows a cross section example of an insulated glass unit comprising a first pane 1 and a second pane 2 spaced apart by a spacer 4. A spacer 4 is sealed to provide a sealed enclosure between the panes 1,2. The seal (not shown) may be a first seal and a secondary seal which may optionally extend across the whole spacer exterior. The spacer 4 has two sides facing the panes 1,2 and an exterior (bottom) which faces away from the enclosed interior space. An intermediate film 3 is positioned in the enclosure by means of the spacer 4 and fixed by means of an insertable spring element 5. The film 3 is clamped between the spring 5 and spacer 4. The film 3 is inserted into a cavity of the spacer 4 and then covered and/or clamped by the spring element 5. The film 3 periphery is under the spring 5 and the film 3 is clamped between the spring 5 on one side and the cavity on the other side. The spacer 4 is adapted for fitting the film 3 in between the substantially rigid spacer 4 and the spring element 5. The spring 5 is in part wrapped by the film 3. The spring 5 covers the film 3 and keeps the film 3 in the cavity.
Generally the cavity may comprise a groove 4c and a shoulder 4e. The film 3 may be clamped by the spring 5 between the groove 4c and the shoulder 4e. The spacer 4 has a cavity configured to insert the spring element 5 whereby the film 3 is fixed and optionally also kept stretched.
Generally the spring element 5 presses the film 3 into a groove 4c by means of a slanted surface 4b (guide). The friction between the spring 5 and the film 3 may wedge the film 3 and spring 5 into the groove 4c and the slanted surface 4b optionally ensure to stretch the film 3 during assembly. By slanted surface 4b is understood a surface slanted in relation to the plane of the installed film 3 and the slant is towards the spacer 4 side. For example a slant angle of 30 to 60 degrees compared to the plane of the stretched film may be employed. Hereby a good wedge effect may be obtained and also enhanced assembly. For example the slanted surface 4b may be a substantially straight line such as an inclined line.
The spacer cavity comprises a slanted portion 4b, slanted in relation to the plane of the stretched film 3 and slant towards the spacer side and terminates in a groove 4c configured to accept one end of the spring element 5. The slanted surface 4b has a shoulder 4e opposite to the groove 4c configured to accept the second end of the spring element 5.
The groove 4c may be substantially V shaped. The groove 4c is narrowing towards its inner end in order to guide the spring 5 and wedge the film 3. The spacer 4 may have a ledge 4f which extends in part over the groove 4c. The ledge 4f covers one end of the spring element 5 whereby the film is folded to provide a good hold. The ledge 4f extends over the spacer cavity. The ledge 4f extends over the spacer cavity and is opposite to a spring 5 fixating shoulder 4e. The ledge 4f bends the film 3 substantially transversally to the plane of the intermediate film 3. Hereby the ledge 4f defines the intermediate film 3 plane/position and enhances the film hold. The spacer cavity has a protruding shoulder 4e opposite the groove 4c, and the shoulder 4e is configured to snap fix the spring element 5. Hereby the spring element 5 is fixed in the cavity by means of the groove 4c and shoulder 4e. This enhances the installation of the film 3 assembly. The spacer 4 comprises one or more grooves that are specially designed for containing a preferably metallic spring element 5 such as a leaf spring, resilient strip, a compressible wedge or a compressible shim.
Figure 2 shows an embodiment with two films 3a and 3b. Hereby insulation may be further enhanced even though assembly requires more effort. The spacer 4 fixates one or more films 3. The spring 5 employs metallic (or less preferred polymer/rubber) spring elements that grip the film 3 tightly, thus dispersing the permanent pull from the film 3 into the spring element 5.
Generally the spring 5 is configured to resist a permanent pull from a film 3. The spring element 5 may comprise shims, wedges, leaf springs, stip springs etc. The spring element 5 is inserted on top of the film 3 in the cavity, so the spring element 5 covers at least part of the film 3 when fixed inside the cavity. In one embodiment the spring element 5 substantially is a plate spring compressed by bending to one side. For example plural spring elements 5 may be employed to clamp or sandwich the film 3. In one example the spring element 5 is a longitudinal member extending along with the spacer 4. In another example the spring element 5 is provided by discrete spring members distributed along the spacer 4. The spring element 5 when inserted has a permanent compression and press the film 3 against the cavity so that the film 3 is clamped between the spring 5 and groove 4c and preferably the film 3 is also clamped between the spring 5 and the shoulder 4e.
In one embodiment, the spacer 4 that holds the film 3 and spring elements 5 could be made of reinforced polyurethane that has good rigidity to resist a permanent pull from a film. The substantially high specific rigidity of reinforced polyurethanes is one approach to solving the issue of spacer bending when using a film with tension. This reinforced and rigid spacer 4 could for example be extruded, cast pultruded in such a way, that it is simultaneously part of the window frame design and/or so that it encapsulates glass sheets and/or polymer sheets (not shown) and optional intermediate sheets in addition to the film. The material of the structurally rigid spacer 4 is made of a metal or polymer; preferably polyurethane reinforced by e.g. glassfibres. If the spacer 4 is made from metal i may be tubular and be roll formed. The spacer may be warm edge type. The spacer 4 is substantially rigid, and this is understood as rigid in order to be suitable to space apart the panes of an insulated glass unit while maintaining a stretched film 3 and accommodating the force from a spring element 5.
Figure 4 illustrates how the film 3 stretch forces may provide a pressure effect, but the example also applies to the other figures. The vertical stretch force from the film 3 is turned by the cavity ledge 4f (or slant 4b) so the spring 5 is forced sideways. Hereby the other end of the spring (distal from the vertical film 3) is pressed towards the shoulder 4e and this enhances the film 3 fix. This mechanism may also help to accommodate the thermal expansion and contraction.
The spacer 4 may comprise a substantially solid and integral profile (in contrast to the conventional hollow tubular spacers), but the solid profile may of course comprise bubbles etc. Examples on fig. 3 and 4 illustrate that the spacer 4 may comprise a first substantially solid profile and may be combined with a second tubular metal profile 6. The second metal profile 6 may face the exterior. Optionally the spacer 4 may comprise plural parts such as a first part 4 configured to fix the film 3 and a second part 6 configured to space apart the IGU panes or configured to ensure a reduced gas leak. The first part 4 may be from polymer while the second part 6 may be from metal such as aluminium. The first part 4 faces the interior of the IGU while the second part 6 faces the exterior of the IGU. The second metal profile 6 may be a thin metal coating for enhancing the gas impermeability.
Generally in order to further improve the film 3 fixation, the surfaces of both the spacer 4 element and the spring element 5 could be modified either structurally (e.g. wrt. roughness) or by coating thus modifying their coefficient of friction.
In one embodiment the spacer 4 comprises solely metallic elements, an additional main advantage is the lack of organic materials (except from the film 3). This means, that there is no degassing of volatile organic compounds from the spacer system.
Generally the spring element 5 may be provided with a bend, profile or separate handle (not shown) for easier handling and assembly.
Further advantages of this invention lie within the ease of production, in which the spring elements 5 are easily clicked into place by either robotic mechanisms or a skilled human worker. One advantage of this system is its gas-impermeability. Current industrial standards for fixing films in IGUs typically comprise two or more separate spacers in which film is fixed in between the spacers being held by different industrial butyles. The main disadvantage of these systems is the butyle being soft and over time allowing film movement and potentially gas leak.
Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations and combinations can be made therein by those skilled in the art without departing from the scope of the appended claims.

Claims

An insulated glass unit spacer system for fixing and suspending a film 3 such as a polymer film; said spacer system comprises at least one film 3, a spacer profile 4 and one or more insertable spring elements 5 wherein:
said spacer profile 4 being configured to space apart two or more substrates such as glass panes 1,2,

said spacer profile has a cavity configured to hold the insertable spring elements 5,

said spacer profile 4 is adapted for fitting the film 3 in between the spacer cavity and the spring element 5,

said spring element 5 fits into the spacer cavity such that when inserted the spring element has a permanent compression and press the film 3 against the cavity,

and said cavity comprises a slanted portion 4b, slanted in relation to the plane of the stretched film 3 and slanted towards the spacer side and terminates in a groove 4c configured to accept the spring element 5.
The insulated glass unit spacer system according to previous claim wherein said spring element 5 fitted into the spacer 4 such that it has a permanent internal compression and therefore when fixed imparting to the film 3 one or more permanent forces having at least one vector component thereof acting at perpendicular angles to the plane of the stretched film 3, so as to increase the frictional force between the film 3 and the spring element 5, on one side, and the spacer cavity on the other side.
The insulated glass unit spacer system according to any previous claims wherein the spring element 5 substantially is a plate spring and the spring 5 covers at least part of the film 3 inside the cavity.
The insulated glass unit spacer system according to any previous claims wherein the spacer 4 profile has a cavity wherein the film 3 is inserted and the cavity has a portion adapted to accommodate the compressed spring element 5, the portion having a span which is smaller than the extended length of the spring element 5 so the spring element is compressed when fixed in the cavity.
The insulated glass unit spacer system according to any previous claims wherein the spacer cavity has a narrowing groove 4c configured to insert the spring element 5 whereby the film 3 is wedged and/or stretched.
The insulated glass unit spacer system according to any previous claims wherein the spacer cavity comprises a slanted portion 4b, slanting in relation to the plane of the stretched film 3 and slanting towards the spacer exterior and terminates in a groove 4c configured to accept one end of the spring element 5.
The insulated glass unit spacer system according to any previous claims wherein the spring element 5 press the film 3 into a groove 4c by means of a slanted surface 4b whereby the spring 5 friction press the film 3 towards the groove 4c
and stretch the film 3.
The insulated glass unit spacer system according to any previous claims wherein the spacer cavity has a protruding shoulder 4e, wherein the shoulder 4e is configured to snap fix the spring element 5.
The insulated glass unit spacer system according to any previous claims wherein the spacer 4 comprises a substantially solid body and optionally is impermeable to gasses by addition of gas impermeable metallic backside facing the exterior.
The insulated glass unit spacer system according to any previous claims comprising an insulated glass unit with at least two panes 1,2 spaced apart by the spacer 4 at their marginal edges, and an intermediate film 3 arranged between the two panes by means of the spacer 4.
The insulated glass unit spacer system according to any previous claim wherein the cavity has a portion which extends under a ledge 4f and the ledge 4f defines the stretched film 3 plane and where the spring element 5 in inserted into said cavity portion.
The insulated glass unit spacer system according to any previous claim wherein the spring element 5 resiliently biases the film 3 down the slanted portion 4b to provide a film 3 stretching effect.
The insulated glass unit spacer system according to any previous claims wherein the spacer cavity comprises a slanted surface 4b extending sideways from the plane of the stretched film 3 wherein the slanted surface 4b is slanted transversally away from the plane of the stretched film 3 and slanted longitudinally away from the centre of the film.
The insulated glass unit spacer system according to any previous claims wherein the spacer comprises a cavity with a substantially V shaped groove 4c which substantially points sideways relative to the plane of the stretched film 3.
Use of an insulated glass unit spacer system according to claim 1-14 for a window or door to fix and suspend a film 3 in the insulated glass unit.